Avalanche Forecast

Moderate - Uncertainty is due to the fact that deep persistent slabs are particularly difficult to forecast.

Aside from a few bouts of potentially strong wind, we continue to be in a rather benign weather pattern at least until Sunday when there is a hint of another strom...

TUESDAY NIGHT: Freezing level returning to valley bottom, moderate north/northwest wind, 1 to 5 cm of snow possible.

WEDNESDAY: Scattered cloud cover initially with some clearing expected in the late afternoon, freezing level near valley bottom, light variable wind at most elevations with moderate northwest wind at the highest elevations, trace of precipitation possible.

THURSDAY: Scattered cloud cover, freezing level rising to around 1500 m in the afternoon, moderate to strong west/southwest wind, trace of precipitation possible.

FRIDAY: Scattered cloud cover, freezing level rising to around 1300 m in the afternoon, moderate to strong wind shifting around from the west, southwest and northwest, trace of precipitation possible.

On Monday reported avalanche activity was limited to small dry loose avalanches and a single small wind slab that succumbed to explosive control work.

Over the weekend numerous natural, human triggered and control work induced avalanches to size 2 were observed, there is a great MIN that serves as an example of this kind of activity here.

There was also a bigger avalanche reported in this MIN on February 9th (check out the photos, they're humbling). The very large avalanche ran on a north facing feature at 2400 m and was triggered by a snowmobile. The group was using excellent travel protocol and thankfully no one was hurt. 10 or so climbs had been made in the same area in the days leading up to this avalanche without incident and that's what makes dealing with persistent slabs so tough.  

Before the above avalanche, the last avalanche cycle to include persistent slabs was during the first weekend in February when some large (size 2.5) deep persistent slab avalanches in the Elk Valley (see photos in this MIN report) ran. These were similar to avalanches in that area from mid-January, which suggests the deep persistent slab problem may resurface during stormy periods.

5 to 15 cm of storm snow from last weekend's storm adds to the variable amounts of wind affected snow that sits above a widespread rain crust that exists up to roughly 2100 m. The storm snow has been formed into slabs by wind from a variety of directions. The Elk Valley has 5-20 cm of snow above the crust and the eastern slopes have 15-35 cm above the crust. There have been observations of surface hoar forming in the Elk Valley previous to Friday Night's storm, check that out here. A well consolidated mid-pack overlies generally weak basal facets, that may be possible to trigger in isolated shallow rocky start zones.

• Avalanche hazard may have improved, but be mindful that deep instabilities are still present.
• Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
• Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
• Caution around slopes that are exposed to cornices overhead.